Prevalence and severity of cornea guttata in the graft following Descemet Membrane Endothelial Keratoplasty (DMEK)

Abstract

Purpose: The aim of this study was to determine the prevalence and severity of cornea guttata (CG) in grafts after Descemet membrane endothelial keratoplasty (DMEK) and to investigate its impact on various clinical parameters during follow-up. Methods: This retrospective study included 664 operations (DMEK and triple-DMEK) on 466 patients. The prevalence and progression of CG after the operation were examined using endothelial specular microscopy images. The severity grade of CG was classified into four grades: G0 without CG, G1 -G3 with increasing severity of CG. Clinical parameters such as central corneal thickness (CCT), visual acuity (VA), endothelial cell density (ECD), pleomorphism and polymegalism were examined during a postoperative follow-up time of 19.6 AE 15.8 months. Results: Cornea guttata (CG) appeared postoperatively in 124 (18.7%) eyes. 112 (16.9%) could be classified as G1, 9 (1.4%) as G2 and only 3 (0.5%) as G3. The examination of clinical parameters showed significant differences between healthy and low-grade CG (G0/G1) and high-grade CG (G2/G3). A significant deterioration was found in the corrected distance visual acuity (CDVA) (p = 0.02). CCT showed an increase between G0 (534 AE 58 lm) and G2 (549 AE 71 lm)/G3 (558 AE 56 lm) with a p-value of 0.02. Additionally, a significant increase in pleomorphism (p = 0.003) and polymegalism (p = 0.04) was detected. Conclusion: Cornea guttata (CG) prevalence after DMEK and triple-DMEK was found to be 18.7%, although most of these cases were classified as low-grade CG and showed no clinical significance. Around 1.9% were classified as high-grade CG and significantly affected several clinical parameters during the follow-up.

Corneal Guttae After Descemet Membrane Endothelial Keratoplasty

“…keratoplasty (PK), corneal guttae were observed in 13% to 26% of the grafts, 6,10,15 for Descemet stripping automated endothelial keratoplasty (DSAEK) in 3% of the grafts (from the same study that reported a rate of 13% after PK), 6 and for DMEK in 4% to19% of the eyes. 11,14 Occurrence of corneal guttae in this case series could be detected within the first postoperative month which corroborates previous reports on the early guttae occurrence after DSAEK and DMEK. 9,11 Along with the fact that corneal guttae have been observed for patients with surgery indications other than FECD, [6][7][8][9][10]12,15 this supports the hypothesis that the corneal guttae originate from the donor tissue.…”

“…10,15 For DMEK, also no effect of guttae on graft survival was reported. 14 In our case series, 2 of 13 grafts (15%) failed, but because this is a small case series, this might not be representative for the actual graft survival probability in the presence of guttae, which might be comparable to the graft survival probability observed in a large DMEK cohort (90% at the 5-year follow-up and 85% at the 10-year follow-up). 22 Corneal guttae are known to affect endothelial cells, 3 but the effect of the observed corneal guttae on postoperative ECD is difficult to quantify because endothelial cell counts on specular microscopy images in the presence of corneal guttae do not tend to be reliable due to a high degree of variability in cell density.…”

“…This may result in donor tissue containing guttae being released for transplantation and guttae becoming visible postoperatively. [6][7][8][9][10][11][12][13][14][15] Reported incidences of postoperative corneal guttae varies in the literature for penetrating and endothelial keratoplasty. For penetrating A-E, Central specular microscopy images of case #4 who underwent primary DMEK for pseudophakic bullous keratopathy.…”

“…This may result in donor tissue containing guttae being released for transplantation and guttae becoming visible postoperatively. 6–15 Reported incidences of postoperative corneal guttae varies in the literature for penetrating and endothelial keratoplasty. For penetrating keratoplasty (PK), corneal guttae were observed in 13% to 26% of the grafts, 6,10,15 for Descemet stripping automated endothelial keratoplasty (DSAEK) in 3% of the grafts (from the same study that reported a rate of 13% after PK), 6 and for DMEK in 4% to19% of the eyes.…”

“…6 The detection of guttae, however, can be challenging, and the occurrence of guttae after corneal transplantation has been reported. [6][7][8][9][10][11][12][13][14][15] Isolated corneal guttae or patches of confluent corneal guttae have been identified in up to 25% of corneal grafts after penetrating keratoplasty 6 and in up to 18.7% of corneal grafts after Descemet membrane endothelial keratoplasty (DMEK). 14 Because DMEK is nowadays a preferred treatment option for endothelial diseases, in the current study, we report in more detail on the different appearances of corneal guttae after DMEK and on the longer-term effect of the guttae on clinical outcomes.…”